High Speed Planar Array Infrared PA-IR Spectrograph


Collapse Biography 

Collapse Overview 
Collapse abstract
Recently a new paradigm for doing infrared (IR) spectroscopy was developed in the Principal Investigator's (Pl's) laboratory. PA-IR uses a focal plane array (FPA) detector onto which a beam of light dispersed by a prism or grating is focused. The broad range of frequencies displayed on the pixel array simultaneously make this a multiplex technique without using the complex scanning mechanism or computational requirements (for Fourier transformation of the data) used in FT-IR interferometry. Thus the no-moving parts configuration of the PA-IR instrument provides the ruggedness required to make the instrument the size of a "shoe-box" and hence portable. In addition the increased sensitivity (100-1000X over single element FT-IR detectors) of the FPA can provide an IR spectrum to be accumulated in as little as 10 microseconds. The only current limitation comes from the frequency range available (3400-2000 cm[-1]) due to the initial availability of only indium-antimonide FPAs during the development of the prototype.

This proposal is to design and construct a portable "broad band" PA-IR instrument that works in the more traditional IR "fingerprint" region (2000-800 cm [-1]) now that Mercury-Cadmium-Telluride FPAs are commercially available and show that it has the sensitivity and speed for in vivo disease prediction/diagnosis. If the PA-IR instrument is coupled with an IR fiber optic sampling probe, it should be possible to characterize ocular tissues in the lens. The advantage of this fiber optic PA-IR technique over conventional dynamic light scattering (DLS) systems currently in use for eye diagnostics is that PA-IR will provide a chemical signature of the various components (collagen IV, gamma-crystallin, etc.) present simultaneously in the "real-time" domain potentially allowing both qualitative and quantitative analysis of the components. For example, PA-IR would allow the detection of protein aggregation (dimers, oligomers) and be able to detect changes in the amount of alpha-helical, beta-sheet or disordered conformation in a protein thereby detecting the onset of cataracts at a very early stage before protein particles become large enough to be detected by DLS. Once this "broad Band" PA-IR is shown to have high sensitivity then other applications such as monitoring the presence of airborne bacteria and viruses in hospital environments becomes feasible as well.


Collapse sponsor award id
R21EB003288

Collapse Time 
Collapse start date
2003-08-01
Collapse end date
2006-01-31